Yes, the best way would be to reformat the hard disk, and then install a fresh operating system (and other programs). However, you would need either a bootable CD or a suitable startup floppy (typically, a Disk Tools disk).
At this point you could do this instead:
a) Place all decoded System 7.5.3 files (one .smi and eighteen .part) in a common folder (New Folder from the File menu).
b) Download the Disk First Aid 7.2.2 .bin file (
here) on the PC, transfer it to the Mac and decode/decompress it. Launch Disk First Aid. Select the hard disk and click Verify. If everything is OK, carry on with c) below. If DFA reports an error, post back.
c) Double-click on the first 7.5.3 file (the .smi). This will mount the total disk image. You will find the installer in the mounted image. Open the installer.
d) Proceed according to Step 7 in KB article #
60717. BTW, the Command key is the one with an Apple.
e) Proceed to Step 8 (but you do not have to update to 7.5.5 right now).
f) If everything is working OK after a restart, you can throw the Previous System Folder and other not wanted files and folders into the Wastebasket (Trash). Empty the Trash from the Special menu.
You should try to create a tools floppy as soon as possible. Post back for more about this.
Jan